Journal of Geodesy, Cartography and Cadastre - No 10 / 2019
Integral issue here
Table of Contents (technical articles)
Improving GNSS Position Accuracy in Urban areas by using Multi-GNSS Technology / Andreea Mihailescu, Iohan Neuner, p. 1-6
Determination of a new gravimetric quasigeoid for Romania / Neculai Avramiuc, Cătălin Erhan, Ileana Spiroiu, Radu-Dan-Nicolae Crişan, Miluţă Flueraş, p. 7-13
Level of Georeferencing (LoGeoRef) using IFC for BIM / Clemen Christian, Görne Hendrik, p. 15-20
Semantic Enrichment of the Geometric Elements of Historical Buildings in the Digital Model / Daniela Paula Safta, Iohan Neuner, p. 21-26
Possibilities for building monitoring, using terrestrial radar interferometry / Aurel Sărăcin, Aurel Florentin Cătălin Negrilă, Tudorel Silviu Clinci, p. 27-33
A contribution to variance analysis of 3D-displacement extracted from GB-SAR measurements / Aiham Hassan, Jinjun Xu, Cheng Xing, Volker Schwieger, p. 35-42
Bicentennial of the Superior School of Land Surveying Engineering in the National Language from Wallachia. Remember: Gheorghe Lazăr / Gheorghe Nistor, Cristian Onu, Gabriel Săndulache, p. 43-47
Analysing Solar Radiation in Suceava / Andreea Mihăilescu, Ana-Cornelia Badea, p. 49-54
Monitoring the deformation of an industrial tank in the discharge and filling process / Constantin Coșarcă, Aurel Sărăcin, Adrian Savu, Aurel Florentin Cătălin Negrilă, p. 55-59
Improving GNSS Position Accuracy in Urban areas by using Multi-GNSS Technology
Andreea Mihailescu, Iohan Neuner
Received: September 2018 / Accepted: October 2018 / Published: March 2019
Abstract
The different global systems have been designed to be compatible. According to the definition of the US space-based position, navigation, and time policy, compatibility refers to the ability of two services to be used separately or together without interfering with each individual service or signal[1]. With advent of new global systems in full operational capability (Glonass, Galileo, BeiDou) offers the ability to improve positioning accuracy by using a combined positioning method. The aim of the paper is to present the manner in which data from several satellite systems can be used concurrently and to emphasize the necessity of adopting a combined GNSS-based solution in difficult environments where the multipath phenomenon is present. The precision obtained using Static Precise Point
Positioning (static - PPP) was analyzed. With an increasing number of satellites the DOP (Dilution of Precision) values decrease, and, consequently, the position accuracy increases. It is analysed SNR (Signal-to-noise ratio) in order to quantify the signal power of the received signal. Carrier-to noise ratio below 34 dbHz characterize weak signal.
Keywords: Multi-GNSS, Galileo, BeiDou, PPP, SNR, DOP, multipath
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Determination of a new gravimetric quasigeoid for Romania
Neculai Avramiuc, Cătălin Erhan, Ileana Spiroiu, Radu-Dan-Nicolae Crişan, Miluţă Flueraş
Received: September 2018 / Accepted: October 2018 / Published: March 2019
Abstract
The project of modeling a gravimetric quasigeoid for Romania is carried out in stages, based on the gravimetric measurements in the area of each county, in the gravimetric points of the 0, 1st and 2nd order gravimetric network, in the checkpoints points (with GNSS/levelling data) and also in the new designed points.
The remove-compute-restore technique was used to remove the long-wavelength component from Global Geopotential Model (GGM) and effect of the short-wavelength signal by applying terrain corrections, to compute residual geoid heights, and to restore the effect of the GGM and topography.
As a preliminary analysis for the development and evaluation of a precise quasigeoid for Romania, different gravimetric geoid solutions were computed using two gravity reduction techniques (Helmert’s second condensation method and the Residual Terrain Model method), and two methodologies to compute residual geoid heights and residual height anomalies (Stokes' integral and Least Squares Collocation).
In this article are presented the main activities that took place in the period 2016-2018 for creating the projects in the counties of Romania and the results obtained till now as well as the perspective for the next years.
Keywords: gravimetric measurements, gravimetric network, modeling, quasigeoid
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Level of Georeferencing (LoGeoRef) using IFC for BIM
Clemen Christian, Görne Hendrik
Received: September 2018 / Accepted: October 2018 / Published: March 2019
Abstract
Using the Industry Foundation Classes (IFC) to georeference building models (BIM) we propose a “pessimistic assumption”, because Building Models in IFC are often not perfectly or sometimes not at all georeferenced, in practice. For this reason, our approach defines a “metric” using standard conform IFC Entities (buildingSmart, ISO 16739:2013) only. The higher the proposed Level of Georeferencing (LoGeoRef) is, the more quality of georeferencing is specified. Each level comprises their own IFC-schema attributes and is standing on its own. The metric is implemented in a free software tool for checking and editing geo-transformation in IFC files.
Keywords: BIM, GIS, IFC, CRS
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Semantic Enrichment of the Geometric Elements of Historical Buildings in the Digital Model
Daniela Paula Safta, Iohan Neuner
Received: September 2018 / Accepted: October 2018 / Published: March 2019
Abstract
Three-dimensional data acquisition technologies are successfully used in the three-dimensional representation of historical buildings of immeasurable value for a nation. In recent years, there is a tendency to extract as much information as possible on these heritage buildings. This article presents the virtual reconstruction of some geometric elements of historical buildings with the aim to use a semantic construction of the digital model. The virtual model will contain both the digital model of the historical building and its cognitive system. The digital model allows to represent building’s architectural elements. It is important that semantic information be included in the 3D digital model, as conceptual and relational data are not highlighted, only pure geometric data playing an essential role in representations.
Thus, after the geometric modeling of the buildings, their semantic modeling will be achieved by semantic enrichment of geometric elements using ontologies.
In order to integrate information from a domain, it is necessary to have a unique representation of ontologies, since ontologies in the same domain can differ as syntax, structure, semantics. As is well known, web applications are receiving information and not raw data. The information will be stored as structured data, so each information has to be modeled at the semantic level, depending on what we want to express.
In conclusion, by using the semantic modeling of historical buildings we can add much more information about these buildings. Many of this information are lost in time. When several important buildings have been modeled using the same unitary structure, they can be represented in a semantic Web.
Keywords: Digital Model, Ontology, Modeling, Cultural Heritage, Semantic Web
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Possibilities for building monitoring, using terrestrial radar interferometry
Aurel Sărăcin, Aurel Florentin Cătălin Negrilă, Tudorel Silviu Clinci
Received: September 2018 / Accepted: October 2018 / Published: March 2019
Abstract
This paper describes the possibility of using a new technology - terrestrial radar interferometry - in order to determine more precisely the deformations and vibrations of building structures. Our attention was directed toward to estimate the horizontal displacements of tall buildings, especially in the upper part, and the vertical displacement of the superstructure of bridges under traffic.
The technology of terrestrial radar interferometry can be used to determine deformations with accuracy up to 0.01 mm in real time, capturing the oscillations of investigated objects with frequency bandwidth up to 200 Hz.
Deformation of several points on the object at different heights can be determined simultaneously, if it is a high building or at different distances (from the point of observation) if it is the deck of a bridge, all of them from the distance and without destructive intervention on the monitored object.
The IBIS-FS radar interferometry system, produced by IDS GeoRadar, was used for measurement in the case of practical examples from this article.
We will briefly outline the measurement principle of this instrument and the criteria underlying the geometry setting for the optimal choice of the observation point.
The article presents several experiments of dynamic analysis of the displacements for the characteristic points of constructions of the type mentioned above.
Keywords: deformations, displacements, monitoring, terrestrial radar interferometry
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A contribution to variance analysis of 3D-displacement extracted from GB-SAR measurements
Aiham Hassan, Jinjun Xu, Cheng Xing, Volker Schwieger
Received: September 2018 / Accepted: October 2018 / Published: March 2019
Abstract
The Ground-Based Synthetic Aperture RADAR (GB-SAR) is a remote sensing technique, which has been used in the last two decades for many monitoring tasks of both manmade and natural objects. The advantages of GB-SAR are its high temporal and spatial resolution and its high accuracy in detection of displacements in LOS-direction for the whole observed area. The major limitation of GB-SAR is the ability to detect just displacement component in LOSdirection; further displacement components cannot be detected. The common method to overcome this problem is to transform the LOS-displacement into a 3D-coordinate
system in which the direction of the real displacement is also defined. For this transformation additional observations are required, which can be observed by means of conventional measurement techniques e.g. GNSS or TLS. The accuracy of the transformed displacement will be affected by the uncertainties of the additional observations. In this study the accuracy of the transformed 3Ddisplacemnt is investigated using a simulation under four different scenarios for the accuracies of the additional
observations. The results of the investigation show high sensitivity of the accuracy to the angle between LOS- and real displacement direction and to the accuracy of the expected real displacement direction. The sensitivity to the accuracy of sensor and pixel position and to the accuracy of the LOS-displacement is very low. The results of the theoretical study are approved through a practical study case.
Keywords: Engineering survey, GB-SAR, Monitoring, Standard Deviation, Error Propagation, 3D-Displacement
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Bicentennial of the Superior School of Land Surveying Engineering in the National Language from Wallachia. Remember: Gheorghe Lazăr
Gheorghe Nistor, Cristian Onu, Gabriel Săndulache
Received: September 2018 / Accepted: October 2018 / Published: March 2019
Abstract
The Superior School of Land Surveying Engineering, the first superior education program in Wallachia, was inaugurated two hundred years ago (1818-2018). This memorable event occurred owe to the arduous efforts of a great patriot, Gheorghe Lazăr, who carved a path for Romanians to pursue science and engineering in their maternal language.
Keywords: Superior education, Wallachia, science
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Analysing Solar Radiation in Suceava
Andreea Mihăilescu, Ana-Cornelia Badea
Received: June 2018 / Accepted: November 2018 / Published: March 2019
Abstract
In this research paper was analysed the solar radiation in a bounded area of Suceava city using Solar Radiation module in ArcGis. Feature classes: buildings, streets and contours were organized in a geospatial database. TIN was generated by using contours feature class in order to obtain solar radiation rasters. We can extrude buidings for a better 3D visualization. For solar radiation analysis, Solar Radiation Tools were used: Area Solar Radiation, Points Solar Radiation and Solar Radiation Graphics. Points solar radiation analysis is used to calculate the amount of radiant energy for a given location. Solar radiation calculations can be performed for specified locations only by using a landscape raster and buildings shapefile. The amount of solar radiation during one year (T0) was calculated. Area Solar analysis is used to compute the insolation across an entire landscape. Different time configurations for analysing solar radiation were used: multi-day time configurations with the maximum range of days a total of one year (2014), special days time configurations and within-day time configurations with the maximum range of time set by one day (24 hours). Solar radiation graphics provides informations on the visibility or obstructions of the sky; related solar map sectors shows changes in elevation/ azimuth; Sun position and skymap provides information on the diffuse radiation areas.
Keywords: Solar radiation, viewshed, sunmap, skymap
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Monitoring the deformation of an industrial tank in the discharge and filling process
Constantin Coșarcă, Aurel Sărăcin, Adrian Savu, Aurel Florentin Cătălin Negrilă
Received: September 2018 / Accepted: October 2018 / Published: March 2019
Abstract
Industrial building structures require revisions and periodical rehabilitation.
In order to update the mathematical model of the structure, it is necessary to determine the different dimensions of the component construction elements, to check the relative positions of the characteristic points of the monitored structure, etc.
This article shows how to monitor a reservoir with ovoid shape, emptying and then filling after it has been rehabilitated and upgraded. The tank has been previously equipped for monitoring by geodetic methods.
The article aims to highlight the working procedure and the accuracy of the results.
The results of the measurements are represented by the coordinates of some object points, which help to deduce the displacements and - respectively - deformations of the building elements at different times in the various stages of the reconstruction works of the objective.
Keywords: monitoring, displacements, deformations, object targets, reference system, settlements
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